open my $FH, '>', '3.0_files_arraydata.txt'
    or die "Cannot open '3.0_files_arraydata.txt' because: $!";

{   local @ARGV = <*.xml>
        or die "Cannot find any '*.xml' files\n";

    while ( <> ) {
        if ( /DATAmessage.*3\.0/ ) {
            print $FH "$ARGV\n";
            close ARGV;
            }
        }
    }